Machines for injection molding synthetic resin materials are relatively common, and such injection molding machines or presses are used by the assignee of the present invention for manufacturing products, such as encapsulated shelves of the type disclosed in U.S. Pat. Nos. 5,540,493 and 5,564,809 granted on Jul. 30, 1996 and Oct. 15, 1996, respectively. The shelf or shelf assembly of the latter patents comprises a generally planar glass shelf panel, a pair of metallic support brackets and a one-piece injection molded encapsulation or encapsulating frame which encapsulates a perimeter edge of the glass panel and a substantial portion of the metallic support brackets. Such shelf assemblies are each manufactured by positioning a pair of support brackets and the glass shelf panel accurately with respect to a pair of mold bodies defining a cavity therebetween, relatively moving the mold bodies to close the same, and injecting synthetic plastic material into a contoured cavity portion to form the encapsulation or encapsulating frame. After the moldable material forming the encapsulating frame sets-up, hardens and cools, the mold bodies are opened and the shelf assembly is removed from the mold.
Conventional presses or injection molding machines are quite massive structures, are quite expensive and once installed the installation thereof is relatively "permanent." The molds are also quite large and are also quite expensive to fabricate. Therefore, considering the capital costs involved, the manufacturer of any type of injection molded product seeks to run an injection molding machine around the clock, twenty-four hours a day, in order to maintain unit costs at a minimum and maximize productivity. Many manufacturers of injection molded products utilize different equipment which is incompatible. For example, a number of injection molding machines in a plant might open and close mold bodies by imparting relative horizontal movement thereto, while other injection molding machines are associated with mold bodies which open and close by relative vertical motion. In a horizontally opening and closing mold a major parting line thereof between the mold bodies occupies a vertical plane and the nozzle of the injection molding machine and the sprue of the mold body or platen is in a generally horizontal plane. The mold opening and closing mechanism imparts relative horizontal motion between the mold bodies to move the same between open and closed positions. In the case of vertical injection, the injection nozzle is disposed vertically, the major parting line of the mold bodies is in a horizontal plane, and the mold bodies are moved vertically relative to each other between opened and closed positions.
It follows from the foregoing that horizontally opening and closing molds and their opening and closing mechanisms cannot be utilized with vertical injection molding machines and likewise vertically opening and closing molds and their opening and closing mechanisms cannot be utilized with horizontal injection molding machines. It likewise follows that if a plant has one line of horizontally opening molds and another line of vertically opening molds, it would be highly desirable if either could be rapidly and inexpensively converted to the other to accommodate fluctuations in product demand, or increase productivity, or the like.